1. Field of the Invention
The present invention relates to a device for the stereophonic recording of sound events by means of two microphones arranged with essentially oppositely directed orientation and mounted in replicas of the human head. The microphones are mounted in the replicas of the outer auditory meatus.
2. Description of the Prior Art
The known so-called dummy-head transmission method has made it possible to obtain a very good quality of sound transmissions in connection with headset reproductions. However, it has not been possible to make this headset reproduction compatible with loudspeaker reproduction. It has been made possible to come closer to compatibility by efforts to use diffuse sound field equalization instead of free sound field equalization of the dummy-head and of the headset. On the other hand, when used in actual transmissions, the dummy-head represents an optical annoyance and, therefore, cannot be used in all situations.
German Offenlegungsschrift 1,927,401 discloses dummy-heads from which the microphones and ear replicas can be removed. A microphone and an ear replica form together a unit. When both units are removed from the dummy-head, the units constitute individual elements which do not have an allocation relative to each other. Thus, in this state, defined recording conditions do not exist, so that it is not possible in this state to use the microphones as if they were mounted in a dummy-head. Accordingly, this type of use is not described in German Offenlegungsschrift 1,927,401.
The article "Kopf-Stereomikrophon fur Amateure" [Head Stereomicrophone for Amateurs], Funkschau 1976, Volume 9, Pages 971-973 (305-307), describes that in the use of microphones with dummy-heads, the quality of reproduction is improved by changing from the use of simple replicas of heads to replicas which include reproductions of the head with hair, beard or the like. In accordance with the present invention, on the other hand, the dummy-head is not used at all.
The article "Natuliches Horen mit kunstlichem Kopf" [Natural Hearing with Artificial Head], Funkschau 1984, Volume 6, pages 41-44, describes the problem that recordings using dummy-heads are only brilliant when reproduced in headsets, but are lacking in quality when reproduced by loudspeakers. This article describes a dummy-head microphone whose recordings are also suitable for loudspeaker production. The reason for this is that the microphones are arranged conventionally in such a way that a diffuse sound field equalization is carried out instead of a free sound field equalization. A number of coupling elements are additionally required for the diffuse sound field equalization.
It has been found that a different solution exists for realizing a transmission through loudspeakers of high quality without having to meet the above-mentioned requirements. Thus, a reproduction of suitably high quality for loudspeakers can be obtained if only the pinnae of the dummy-head are used and microphones of the type are used which operate as directional microphones in the low-frequency range of up to about 1500 Hz and, in the frequency range above 1500 Hz, operate with spectral resolution of the outer ear transmission function. Also, this has the advantage that additional acoustic effects can be achieved by modifying the pickup pattern and the position of the pinnae.
It is the object of the present invention to provide a device of the above-mentioned type for the stereophonic recording of sound events in which the use of a complete replica of the human head is avoided and the headset reproduction and loudspeaker reproduction are compatible. In addition, a number of modifications of the sound reception are to be made possible.